My Class b, 1997 Xplorer 230XL, has all the plumbing inside the heated space, but nothing on the grey water tank underneath. My freshwater tank & pump are under the bed which is an enclosed area without heat input though, so it depends on heat warming the areas walls. I was turkey hunting in WY in April and 1 morning it was 8. The lines to the water pump froze. No permanent damage after I thawed that out. I also use it deer hunting and one year even the fresh water tank froze solid. I was using my electic heater while at home and the power got disconnected. It took 2 days to thaw it and I was lucky no damage again. We're going to 20 the next 2 nights & I'll be using electric heat, popping up the water tank area cover to help heat get in and running extension cords in there with 40 watt light bulbs to give some extra heat.
I hope your new Travato works as well in the cold as my 20 year old B.
